Diesel engines are the preferred means of producing torque for use in a wide range of applications ranging from uses in transportation such as heavy-duty trucks and trains, off-road agricultural and mining equipment to the large scale production of on-site electrical power to name a few. Their virtually unmatched power to mass ratios and the relative safety of their fuel makes them almost the only choice for use in applications such as long-haul trucks, tractors, earth movers, combines, surface mining equipment, non-electric locomotives, high capacity emergency power generators and the like.
Diesel engines operate at high internal temperature. One consequence of their high operating temperatures is that at least some of the Nitrogen present in the engine at the moment of combustion may combine with Oxygen to form NOx including species such as NO and NO2. Another consequence of their high operating temperatures is that diesel exhaust at or near the point of exit from the engine is very hot.
A compound such as NOx is problematic because it readily combines with volatile organic compounds in the atmosphere to form smog. NOx is regarded as a pollutant and virtually every industrialized nation regulates the levels of NOx that can be legally discharged into the atmosphere. The regulation governing NOx emissions are expected to become even stricter. Fortunately, engine and equipment manufacturers have developed systems for reducing the levels of NO produced by the combustion of diesel fuel and released into the environment. Still, with even tighter limits on the amounts of these compound that can be released into the atmosphere there remains a need for improved materials and methods for reducing the levels of NOx; some aspects of the instant invention address this need.